NAME

       hosts.equiv  - list of hosts and users that are granted "trusted" r command access to your
       system

DESCRIPTION

       The file /etc/hosts.equiv allows or denies hosts and users to use  the  r-commands  (e.g.,
       rlogin, rsh, or rcp) without supplying a password.

       The file uses the following format:

       +|[-]hostname|+@netgroup|-@netgroup [+|[-]username|+@netgroup|-@netgroup]

       The hostname is the name of a host which is logically equivalent to the local host.  Users
       logged into that host are allowed to access like-named user accounts  on  the  local  host
       without  supplying  a  password.   The hostname may be (optionally) preceded by a plus (+)
       sign.  If the plus sign is used alone, it allows any host to access your system.  You  can
       explicitly  deny  access  to  a host by preceding the hostname by a minus (-) sign.  Users
       from that host must always supply additional credentials, including possibly  a  password.
       For  security  reasons  you  should  always use the FQDN of the hostname and not the short
       hostname.

       The username entry grants a specific user  access  to  all  user  accounts  (except  root)
       without  supplying  a  password.   That  means  the  user  is NOT restricted to like-named
       accounts.  The username may be (optionally) preceded by a plus (+)  sign.   You  can  also
       explicitly deny access to a specific user by preceding the username with a minus (-) sign.
       This says that the user is not trusted no matter what other entries for that host exist.

       Netgroups can be specified by preceding the netgroup by an @ sign.

       Be extremely careful when using the plus (+) sign.  A  simple  typographical  error  could
       result  in  a  standalone  plus sign.  A standalone plus sign is a wildcard character that
       means "any host"!

FILES

       /etc/hosts.equiv

NOTES

       Some systems will honor the contents of this file only when it has owner root and no write
       permission  for anybody else.  Some exceptionally paranoid systems even require that there
       be no other hard links to the file.

       Modern systems use the  Pluggable  Authentication  Modules  library  (PAM).   With  PAM  a
       standalone  plus  sign is considered a wildcard character which means "any host" only when
       the word promiscuous is added to the  auth  component  line  in  your  PAM  file  for  the
       particular service (e.g., rlogin).

EXAMPLE

       Below are some example /etc/host.equiv or ~/.rhosts files.

       Allow any user to log in from any host:

           +

       Allow any user from host with a matching local account to log in:

           host

       Note:  the  use of +host is never a valid syntax, including attempting to specify that any
       user from the host is allowed.

       Allow any user from host to log in:

           host +

       Note: this is distinct from the previous example since it  does  not  require  a  matching
       local account.

       Allow user from host to log in as any non-root user:

           host user

       Allow all users with matching local accounts from host to log in except for baduser:

           host -baduser
           host

       Deny all users from host:

           -host

       Note: the use of -host -user is never a valid syntax, including attempting to specify that
       a particular user from the host is not trusted.

       Allow all users with matching local accounts on all hosts in a netgroup:

           +@netgroup

       Disallow all users on all hosts in a netgroup:

           -@netgroup

       Allow all users in a netgroup to log in from host as any non-root user:

           host +@netgroup

       Allow all users with matching local accounts on all hosts in a netgroup except baduser:

           +@netgroup -baduser
           +@netgroup

       Note: the deny statements must always precede the allow statements  because  the  file  is
       processed sequentially until the first matching rule is found.

SEE ALSO

       rhosts(5), rlogind(8), rshd(8)

COLOPHON

       This  page  is  part of release 4.15 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at https://www.kernel.org/doc/man-pages/.